1. Field of the Invention
This invention relates to silica particles modified by at least one type of organic group.
2. Description of the Prior Art
Silica particles are widely used as filler in resin compositions employed as sealants in integrated circuit devices (ICs) and other electronic components.
The steady increase in the packing density of ICs in recent years has led to demand for sealants with outstanding thermal shock resistance and toughness. In response to this demand, efforts have been made to improve the quality of the silica particles used as filler in these sealants. Attempts have also been made to improve the toughness and other properties of silica particles for use as filler in various types of resin-type composite materials other than sealants. Up to now, however, no pronounced improvement in the properties of resin compositions has actually been realized through improvement of the properties of the silica particles used as filler therein.
Through his studies in connection with a particular process used for the production of spherical silica particles, namely the sol-gel process, the inventors discovered that the addition of an alkoxy-silane having a specific organic functional results in the production of silica particles having a specific organic modifier group and that these silica particles dramatically improve the properties of resin products in which they are used as filler.